Can tricuspid regurgitation (TR) improve following mitral valve repair?

Tricuspid Regurgitation Improvement Following Mitral Valve Repair

Yes, tricuspid regurgitation (TR) can improve following mitral valve repair, particularly when the TR is secondary to pulmonary hypertension caused by mitral valve disease. This improvement is more likely to occur in patients with specific characteristics and hemodynamic patterns.

Mechanisms of TR Improvement After Mitral Valve Repair

• When TR coexists with mitral stenosis or regurgitation, pulmonary hypertension is often present, which contributes to the TR development 1
• After successful mitral valve repair or valvotomy, pulmonary hypertension and TR almost always diminish if the tricuspid valve anatomy is not grossly distorted 1
• The reduction in left atrial pressure following mitral valve repair leads to decreased pulmonary artery pressure, which reduces right ventricular afterload and improves tricuspid valve function 1

Predictors of TR Improvement After Mitral Valve Repair

• TR is more likely to improve when:

  • Pulmonary hypertension is severe and the tricuspid valve anatomy is not grossly distorted 1
  • The tricuspid annulus is not significantly dilated (diameter <35 mm or <21 mm/m²) 1
  • There is no severe tethering of the tricuspid valve leaflets (tenting area <1 cm²) 1
  • The TR is functional rather than due to organic tricuspid valve disease 1

• TR is less likely to improve when:

  • There is severe rheumatic deformity of the tricuspid valve 1
  • Significant tricuspid annular dilatation is present 1
  • Severe TR is present before surgery 2, 3
  • Right ventricular dysfunction exists preoperatively 2, 4

Evidence on TR Improvement After Mitral Valve Repair

• In patients with mild to moderate preoperative TR, mitral valve repair alone is associated with reduced TR and mild worsening of right ventricular function initially, with improvement over time 2
• Studies show that approximately one-third of patients experience a significant decrease in TR severity (by at least one grade) following percutaneous mitral valve repair 5
• The reduction in systolic pulmonary artery pressure (SPAP) is the most significant predictor of TR improvement after mitral valve repair 5

When to Consider Concomitant Tricuspid Valve Repair

• Concomitant tricuspid annuloplasty should be considered during mitral valve surgery when:

  • Severe TR is present 1
  • Moderate TR with dilated annulus (≥40 mm or >21 mm/m²) is present 1
  • There are preoperative signs or symptoms of right-sided heart failure 1
  • Significant tricuspid annular dilatation exists, even if TR is mild 1

• Evidence suggests that concomitant tricuspid valve repair:

  • Effectively eliminates severe TR and improves right ventricular function 2
  • Provides more durable results than mitral valve repair alone in patients with significant TR 2, 6
  • Improves functional status independent of the degree of TR when based on tricuspid dilatation 1

Clinical Implications and Monitoring

• Patients with mild/moderate TR at follow-up after mitral valve repair have lower event rates compared to those with severe TR 4
• Regular echocardiographic follow-up is essential to monitor TR progression and right ventricular function after mitral valve repair 3
• Despite improvement in TR after mitral valve repair, up to 20-50% of patients may develop recurrent TR if no concomitant tricuspid intervention was performed 1, 3

Common Pitfalls to Avoid

• Failing to assess the severity of TR and tricuspid annular dimensions before mitral valve surgery 1
• Underestimating the importance of tricuspid valve tethering as a predictor of residual TR after surgery 1
• Not considering concomitant tricuspid annuloplasty in patients with atrial fibrillation and TR, as atrial fibrillation is a predictor of failure of TR improvement 6
• Overlooking the impact of right ventricular function on TR improvement after mitral valve surgery 2, 4

In summary, while TR can improve following mitral valve repair, particularly when related to pulmonary hypertension with normal tricuspid valve morphology, concomitant tricuspid valve repair should be strongly considered in patients with significant TR or tricuspid annular dilatation to ensure more durable results and better long-term outcomes.